Continuation vs Awaiting.

Program.cs

using System;
using System.Threading.Tasks;

namespace ConsoleApp5
{
    public static class Program
    {
        private static async Task ContinuationWithAwaitingSimple()
        {
            Console.WriteLine("Before");

            await Task.Delay(5000);

            Console.WriteLine("After");
        }

        private static Task ContinuationWithDelegateSimple()
        {
            Console.WriteLine("Before");

            return Task.Delay(5000).ContinueWith(task =>
            {
                Console.WriteLine("After");
            });
        }

        private static async Task ContinuationWithAwaitingComplex()
        {
            Console.WriteLine("Before");

            for (var index = 0; index < 10; index++)
            {
                await Task.Delay(1000);
                Console.WriteLine("Interval: " + index);
            }

            Console.WriteLine("After");
        }

        private static Task ContinuationWithDelegateComplex()
        {
            Console.WriteLine("Before");

            var tcs = new TaskCompletionSource<object>();

            var index = 0;
            void continuation(Task task)
            {
                Console.WriteLine("Interval: " + index);
                index++;
                if (index < 10)
                {
                    Task.Delay(1000).ContinueWith(continuation);
                }
                else
                {
                    Console.WriteLine("After");
                    tcs.SetResult(null);
                }
            };

            Task.Delay(1000).ContinueWith(continuation);

            return tcs.Task;
        }

        static async Task Main(string[] args)
        {
            await ContinuationWithDelegateSimple();
            await ContinuationWithAwaitingSimple();
            await ContinuationWithDelegateComplex();
            await ContinuationWithAwaitingComplex();
        }
    }
}